Media captionIn Staten Island, neighbours and friends of Eric Garner told the BBC about their anger after the grand jury ruling came through

The US justice department is to launch a civil rights investigation into the death of Eric Garner, a black man who was placed in an apparent chokehold by a white New York police officer.

The inquiry was announced by Attorney General Eric Holder after a grand jury decided against charging the officer.

That decision prompted street protests in New York. Activists have called for a march in Washington next week.

President Barack Obama said the case spoke to "larger issues".

Mr Garner, 43, was stopped on a street in New York on 17 July on suspicion of selling loose, untaxed cigarettes.

After a confrontation with police he was wrestled to the ground and restrained by force. He became unresponsive and later died.

America saw a wave of race-related unrest only last week over the decision not to indict another white police officer who had shot dead a young black man in Ferguson, Missouri.

Announcing "an independent, thorough, fair and expeditious" investigation into potential civil rights violations in the chokehold case, Mr Holder said he was continuing a review of how to heal a "breakdown in trust" between police and communities.

The justice department, he said, would conduct a "complete review" of material gathered in the local investigation. "All lives must be valued - all lives," he added.

Nick Bryant, BBC News, New York

In isolation, the decision of the grand jury in Staten Island not to indict the white NYPD officer Daniel Pantaleo would have sparked anger.

The fact that it came less than 10 days after a grand jury in Missouri decided that the white officer involved in the shooting of Michael Brown should not face criminal charges has amplified the sense of racial injustice felt by those who believe the decision is inexplicable.

In contrast to Ferguson, there is video evidence showing what happened in Staten Island. New York's medical examiner had already ruled that the death of Eric Garner was a homicide, and that the chokehold contributed to it.

Even though America has a black president and a black attorney general, Eric Holder, this will reinforce the widespread feeling in poor African-American communities that the criminal justice system is weighted against them, and that the law is not colour-blind.